public class App extends Application {
    private Context context;
    private Activity activity;
    private static App sInstance;
    public static synchronized App getInstance() {
        return sInstance;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        sInstance = this;
        context = getApplicationContext();
        Commune.CommuneCsvToDatabase(App.getInstance().getContext());
    }

    public Context getContext() {
        return context;
    }

    public Activity getCurrentAct() {
        return activity;
    }

    public void setCurrentAct(Activity activity) {
        this.activity = activity;
    }
 }

CommuneDatabase communeDatabase = new CommuneDatabase(App.getInstance().getContext());
ArrayList<Commune> communes = communeDatabase.getAllCommune();